Clark Lin / Mbed 2 deprecated BX-car_s

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Dependencies:   mbed-rtos mbed

Fork of BX-car_s by Tony Lin

bx-adc.h@23:d6d4e8adf7fe, 2014-07-02 (annotated)

Committer:
physicsgood
Date:
Wed Jul 02 13:33:49 2014 +0000
Revision:
23:d6d4e8adf7fe
Parent:
1:82bc25a7b68b 
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backman 1:82bc25a7b68b 1 #include "mbed.h"
backman 1:82bc25a7b68b 2 #include "pinmap.h"
backman 1:82bc25a7b68b 3
backman 1:82bc25a7b68b 4
backman 1:82bc25a7b68b 5
backman 1:82bc25a7b68b 6 /** A class similar to AnalogIn, only faster, for LPC1768, LPC408X and KLxx
backman 1:82bc25a7b68b 7 *
backman 1:82bc25a7b68b 8 * AnalogIn does a single conversion when you read a value (actually several conversions and it takes the median of that).
backman 1:82bc25a7b68b 9 * This library runns the ADC conversion automatically in the background.
backman 1:82bc25a7b68b 10 * When read is called, it immediatly returns the last sampled value.
backman 1:82bc25a7b68b 11 *
backman 1:82bc25a7b68b 12 * LPC1768 / LPC4088
backman 1:82bc25a7b68b 13 * Using more ADC pins in continuous mode will decrease the conversion rate (LPC1768:200kHz/LPC4088:400kHz).
backman 1:82bc25a7b68b 14 * If you need to sample one pin very fast and sometimes also need to do AD conversions on another pin,
backman 1:82bc25a7b68b 15 * you can disable the continuous conversion on that ADC channel and still read its value.
backman 1:82bc25a7b68b 16 *
backman 1:82bc25a7b68b 17 * KLXX
backman 1:82bc25a7b68b 18 * Multiple Fast instances can be declared of which only ONE can be continuous (all others must be non-continuous).
backman 1:82bc25a7b68b 19 *
backman 1:82bc25a7b68b 20 * When continuous conversion is disabled, a read will block until the conversion is complete
backman 1:82bc25a7b68b 21 * (much like the regular AnalogIn library does).
backman 1:82bc25a7b68b 22 * Each ADC channel can be enabled/disabled separately.
backman 1:82bc25a7b68b 23 *
backman 1:82bc25a7b68b 24 * IMPORTANT : It does not play nicely with regular AnalogIn objects, so either use this library or AnalogIn, not both at the same time!!
backman 1:82bc25a7b68b 25 *
backman 1:82bc25a7b68b 26 * Example for the KLxx processors:
backman 1:82bc25a7b68b 27 * @code
backman 1:82bc25a7b68b 28 * // Print messages when the AnalogIn is greater than 50%
backman 1:82bc25a7b68b 29 *
backman 1:82bc25a7b68b 30 * #include "mbed.h"
backman 1:82bc25a7b68b 31 *
backman 1:82bc25a7b68b 32 * FastAnalogIn temperature(PTC2); //Fast continuous sampling on PTC2
backman 1:82bc25a7b68b 33 * FastAnalogIn speed(PTB3, 0); //Fast non-continuous sampling on PTB3
backman 1:82bc25a7b68b 34 *
backman 1:82bc25a7b68b 35 * int main() {
backman 1:82bc25a7b68b 36 * while(1) {
backman 1:82bc25a7b68b 37 * if(temperature > 0.5) {
backman 1:82bc25a7b68b 38 * printf("Too hot! (%f) at speed %f", temperature.read(), speed.read());
backman 1:82bc25a7b68b 39 * }
backman 1:82bc25a7b68b 40 * }
backman 1:82bc25a7b68b 41 * }
backman 1:82bc25a7b68b 42 * @endcode
backman 1:82bc25a7b68b 43 * Example for the LPC1768 processor:
backman 1:82bc25a7b68b 44 * @code
backman 1:82bc25a7b68b 45 * // Print messages when the AnalogIn is greater than 50%
backman 1:82bc25a7b68b 46 *
backman 1:82bc25a7b68b 47 * #include "mbed.h"
backman 1:82bc25a7b68b 48 *
backman 1:82bc25a7b68b 49 * FastAnalogIn temperature(p20);
backman 1:82bc25a7b68b 50 *
backman 1:82bc25a7b68b 51 * int main() {
backman 1:82bc25a7b68b 52 * while(1) {
backman 1:82bc25a7b68b 53 * if(temperature > 0.5) {
backman 1:82bc25a7b68b 54 * printf("Too hot! (%f)", temperature.read());
backman 1:82bc25a7b68b 55 * }
backman 1:82bc25a7b68b 56 * }
backman 1:82bc25a7b68b 57 * }
backman 1:82bc25a7b68b 58 * @endcode
backman 1:82bc25a7b68b 59 */
backman 1:82bc25a7b68b 60 class FastAnalogIn {
backman 1:82bc25a7b68b 61
backman 1:82bc25a7b68b 62 public:
backman 1:82bc25a7b68b 63 /** Create a FastAnalogIn, connected to the specified pin
backman 1:82bc25a7b68b 64 *
backman 1:82bc25a7b68b 65 * @param pin AnalogIn pin to connect to
backman 1:82bc25a7b68b 66 * @param enabled Enable the ADC channel (default = true)
backman 1:82bc25a7b68b 67 */
backman 1:82bc25a7b68b 68 FastAnalogIn( PinName pin, bool enabled = true );
backman 1:82bc25a7b68b 69
backman 1:82bc25a7b68b 70 ~FastAnalogIn( void )
backman 1:82bc25a7b68b 71 {
backman 1:82bc25a7b68b 72 disable();
backman 1:82bc25a7b68b 73 }
backman 1:82bc25a7b68b 74
backman 1:82bc25a7b68b 75 /** Enable the ADC channel
backman 1:82bc25a7b68b 76 *
backman 1:82bc25a7b68b 77 * @param enabled Bool that is true for enable, false is equivalent to calling disable
backman 1:82bc25a7b68b 78 */
backman 1:82bc25a7b68b 79 void enable(bool enabled = true);
backman 1:82bc25a7b68b 80
backman 1:82bc25a7b68b 81 /** Disable the ADC channel
backman 1:82bc25a7b68b 82 *
backman 1:82bc25a7b68b 83 * Disabling unused channels speeds up conversion in used channels.
backman 1:82bc25a7b68b 84 * When disabled you can still call read, that will do a single conversion (actually two since the first one always returns 0 for unknown reason).
backman 1:82bc25a7b68b 85 * Then the function blocks until the value is read. This is handy when you sometimes needs a single conversion besides the automatic conversion
backman 1:82bc25a7b68b 86 */
backman 1:82bc25a7b68b 87 void disable( void );
backman 1:82bc25a7b68b 88
backman 1:82bc25a7b68b 89 /** Returns the raw value
backman 1:82bc25a7b68b 90 *
backman 1:82bc25a7b68b 91 * @param return Unsigned integer with converted value
backman 1:82bc25a7b68b 92 */
backman 1:82bc25a7b68b 93 unsigned short read_u16( void );
backman 1:82bc25a7b68b 94
backman 1:82bc25a7b68b 95 /** Returns the scaled value
backman 1:82bc25a7b68b 96 *
backman 1:82bc25a7b68b 97 * @param return Float with scaled converted value to 0.0-1.0
backman 1:82bc25a7b68b 98 */
backman 1:82bc25a7b68b 99 float read( void )
backman 1:82bc25a7b68b 100 {
backman 1:82bc25a7b68b 101 unsigned short value = read_u16();
backman 1:82bc25a7b68b 102 return (float)value * (1.0f/65535.0f);
backman 1:82bc25a7b68b 103 }
backman 1:82bc25a7b68b 104
backman 1:82bc25a7b68b 105 /** An operator shorthand for read()
backman 1:82bc25a7b68b 106 */
backman 1:82bc25a7b68b 107 operator float() {
backman 1:82bc25a7b68b 108 return read();
backman 1:82bc25a7b68b 109 }
backman 1:82bc25a7b68b 110
backman 1:82bc25a7b68b 111
backman 1:82bc25a7b68b 112 private:
backman 1:82bc25a7b68b 113 bool running;
backman 1:82bc25a7b68b 114 char ADCnumber;
backman 1:82bc25a7b68b 115 uint32_t *datareg;
backman 1:82bc25a7b68b 116 };
backman 1:82bc25a7b68b 117